Major contaminants including, for instance, oils such as gasoline, naphtha, kerosene or Bunker C oil, toxic chemicals such as BTEX, and the like, have been leading to severe environmental contamination of nearby soil and groundwater due to poor degradability and serious toxicity.
Conventional technology for treatment of such contaminants in the soil or groundwater includes physical or chemical treatment, which, however, often has limited applicability because significant running costs are required and the soil ecosystem are severely ruined. One solution that has been proposed in recent years is biological treatment based on biodegradation by indigenous microorganisms in the contaminated soil and groundwater. However, one drawback of the use of biological treatment is that oil-to-soil cohesion or low water solubility, which results from lipophilic or hydrophobic properties of oils and toxic chemicals, makes biodegradation by the microorganisms difficult to achieve. Other problems associated with the use of biological treatment include a long process time is required and highly toxic contaminants may adversely affect activity of indigenous microorganisms, considerably lowering the overall treatment efficiency.